Switching drum catch and trip device



Dec. 12, 1967 D. R. SELF SWITCHING DRUM CATCH AND TRIP DEVICE Filed Feb. 8, 1966 Dolfy R Self,

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United States Patent 3,357,261 SWITCHING DRUM CATCH AND T DEVICE Dolty R. Self, Hatch, N. Mex., assignor to the United States of America as represented by the Secretary of the Army Fiied Feb. 8, 1966, Ser. No. 526,337 3 Claims. (CI. 74-15) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to a catch and trip device that is used as part of the film exposure mechanism of a camera.

In film exposure mechanisms of this type, the actuating portion of the mechanism is released for film transport and stopped for film exposure. This cycle is repeated approximately five times per second, and in order to be capable of performing this function for a considerable length of time, the catch and trip device must be so designed as to have a minimum amount of wearing contact between the associated elements of the catch and trip device.

With the above need in mind, it is an object of this invention to provide a catch and trip device that can be tripped and reset with a minimum amount of wearing contact between the several parts.

Another object of this invention is to provide a catch arm that is spring biased into an unlatching position.

Still another object of this invention is to provide a latching pin for a catch arm that has sliding contact with a portion of the catch arm to allow the catch arm to be released.

In accordance with this invention, a switching drum catch and trip device is provided that has actuating mechanism that is rotatably mounted. A conventional spring type device is connected to the actuating mechanism to rotate said actuating mechanism. A catch plate is secured to the actuating mechanism for rotation therewith and includes two projecting stop members that areoppositely disposed on the catch plate. A catch arm is pivotally mounted intermediate its ends on support structure adjacent the catch plate. One end of the catch arm is generally L-shaped to define a latch surface for latching engagement with the stop members. The other end of the catch arm has a curved cam surface for contacting a side of the stop members to actuate and reset the catch arm in a latching position. A spring biased plunger bears against the cam surface end of the catch arm for biasing the catch arm to an unlatched position, and a latch member coacts with a latching notch on said one end of the catch arm for holding the catch arm in a latching position.

In the accompanying drawing forming a part of this specification, and in which like numerals are employed to designate corresponding parts throughout the same:

FIGURE 1 is a perspective view illustrating a switching drum catch and trip device with the catch arm in a latching position;

FIGURE 2 is a perspective view illustrating a switching drum catch and trip device in a tripped position; and

FIGURE 3 is a perspective view illustrating a switching drum catch and trip device as the cam coacts with a stop member to actuate the catch arm to the latching position.

The invention may be better understood by referring to the drawing in which, numeral 1 designates a support plate. Shaft 3 is rotatably mounted relative to support plate 1 in a conventional manner and is connected to a conventional spring motor actuating means (not shown) on the back side of support plate 1 for rotatably biasing shaft 3. A batch plate 5 and other gear means are mounted on shaft 3 in a conventional manner to be rotated by shaft 3. Catch plate 5 has projecting stop members 7 and 9 for engaging catch arm 11 and holding catch plate 5 and shaft 3 in a stationary position against the actuating force of the spring motor actuating means.

Catch arm 11 is pivotably mounted in mounting block 13 by pivot pin 15, and mounting block 13 is secured to support plate 5 such as by bolts 17. Catch arm 11 has cam surface 19 at one end for coaction with stop members 7 and 9 to actuate the catch arm to a reset latching position. The other end of catch arm 11 has a radially extending latch surface 21 for coaction with stop members 7 and 9 to hold catch plate 5 against rotation until released. At the cam surface end of catch lever 11, a plunger 23 is located in bore 25 and is biased into engagement with catch arm 11 to bias the catch arm toward an unlatched position by spring 27 reacting between shoulder 29 on plunger 23 and threadably mounted adjusting screw 31. Catch arm 11 is held in latching position by pin 33 coacting with notch 35 defined between member 37 and a portion of the catch arm. Pin 33 is biased toward the latching position and actuated to the unlatching position by conventional relay means 39. Pin 33 has a flat side 41 for contacting fiat surface 43 on member 37 to provide a sliding action between pin 33 and member 37 when pin 33 is actuated to unlatched position relative to catch arm 11.

In operation, with catch arm 11 in the latching position against stop member 7, the relay for pin 33 is momentarily energized to actuate pin 33 to the unlatching position, illustrated in FIGURE 2, to allow spring 27 to actuate plunger 23 and in turn catch arm 11 to unlatched position. With catch arm 11 in the unlatched position, catch plate 5 will rotate counterclockwise until stop member 9 contacts cam surface 19 and actuates catch arm 11 into the latching position. Since the relay for pin 13 was only momentarily energized, pin 33 will reengage notch 35 and maintain catch arm 11 in the latching position until the relay for pin 33 is again energized.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the size, shape and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

I claim:

1. A catch and trip device including: support means; a shaft rotatably mounted relative to said support means and biased for rotation in one direction; a catch plate mounted on said shaft and having stop members at the periphery thereof and located directly opposite each other; a mounting block mounted on said support means and adjacent said catch plate; a catch arm pivotably mounted intermediate its ends on said mounting block; said catch arm having cam surface means on one end for coaction with said stop members for actuating said catch arm to a latching position, the other end of said catch arm having a catch surface for coacting with said stop members for holding said catch plate in a latched position; means biasing said catch arm toward an unlatched position; and means holding said catch arm in the latching position against said biasing means.

2. A catch and trip device as set forth in claim 1, wherein said biasing means includes a plunger mounted in a bore of said mounting block and bearing against the side of said catch arm opposite said cam surface means, an adjustable screw threadably mounted in said bore, and a spring between said screw and plunger biasing said plunger to actuate said catch arm toward an unlatched position.

3. A catch and trip device as set forth in claim 1, wherein said holding means includes a notch defined by said catch arm, a pin biased into engagement with said notch for holding said catch arm in latching position against said biasing means, and a relay connected to said pin for actuating said pin away from said notch to allow said biasing means to actuate said catch arm to an unlatched position.

References Cited UNITED STATES PATENTS 9/1934 Barenyi 741.S 4/1963 Theenhausen et al. 74-1.5 X

MILTON KAUFMAN, Primary Examiner. 

1. A CATCH AND TRIP DEVICE INCLUDING: SUPPORT MEANS; A SHAFT ROTATABLY MOUNTED RELATIVE TO SAID SUPPORT MEANS AND BIASED FOR ROTATION IN ONE DIRECTION; A CATCH PLATE MOUNTED ON SAID SHAFT AND HAVING STOP MEMBERS AT THE PERIPHERY THEREOF AND LOCATED DIRECTLY OPPOSITE EACH OTHER; A MOUNTING BLOCK MOUNTED ON SAID SUPPORT MEANS AND ADJACENT SAID CATCH PLATE; A CATCH ARM PIVOTALLY MOUNTED INTERMEDIATE ITS END ON SAID MOUNTING BLOCK; SAID CATCH ARM HAVING CAM SURFACE MEANS ON ONE END OF COACTION WITH SAID STOP MEMBERS FOR ACTUATING SAID CATCH ARM TO A LATCHING POSITION, THE OTHER END OF SAID CATCH ARM HAVING A CATCH SURFACE FOR COACTING WITH SAID STOP MEMBERS FOR HOLDING SAID CATCH PLATE IN A LATCHED POSITION; MEANS BIASING SAID CATCH ARM TOWARD AN UNLATCHED POSITION; AND MEANS HOLDING SAID CATCH ARM IN THE LATCHING POSITION AGAINST SAID BIASING MEANS. 